package com.huashi.dealer.modular.business.cart.service.impl;

import com.huashi.dealer.modular.business.cart.param.CartResponseParam;
import com.huashi.dealer.modular.business.cart.service.CheckoutService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * 购物车结算服务实现类
 * 对应PHP的Checkout服务
 *
 * @author 谭陈强
 * @since 2025-01-27
 */
@Slf4j
@Service
public class CheckoutServiceImpl implements CheckoutService {

    @Override
    public CartResponseParam onCheckout(Long userId, List<CartResponseParam.CartGoodsInfo> goodsList) {
        CartResponseParam responseParam = new CartResponseParam();
        
        try {
            // 设置基础商品信息
            responseParam.setGoodsList(goodsList);
            
            // 计算商品总数量和总金额
            int totalNum = 0;
            BigDecimal totalPrice = BigDecimal.ZERO;
            for (CartResponseParam.CartGoodsInfo goods : goodsList) {
                totalNum += (goods.getGoodsNum() == null ? 0 : goods.getGoodsNum());
                totalPrice = totalPrice.add(goods.getGoodsTotalPrice() == null ? BigDecimal.ZERO : goods.getGoodsTotalPrice());
            }
            
            responseParam.setCartTotalNum(totalNum);
            responseParam.setCartTotalPrice(totalPrice);
            responseParam.setCartCount(goodsList.size());
            responseParam.setUserId(userId);
            
            // TODO: 实现以下结算功能
            // 1. 会员折扣计算
            // 2. 优惠券列表获取
            // 3. 积分抵扣计算
            // 4. 配送方式设置
            // 5. 满赠商品获取
            // 6. 最终结算金额计算
            
            log.info("购物车结算完成，用户ID: {}, 商品数量: {}, 总金额: {}", userId, totalNum, totalPrice);
            
        } catch (Exception e) {
            log.error("购物车结算失败，用户ID: {}", userId, e);
            throw new RuntimeException("购物车结算失败：" + e.getMessage());
        }
        
        return responseParam;
    }

    @Override
    public List<Object> getUserCouponList(Long userId, BigDecimal orderTotalPrice) {
        // TODO: 实现用户优惠券列表获取
        // 1. 查询用户未使用的优惠券
        // 2. 过滤满足使用条件的优惠券
        // 3. 按优惠金额排序
        log.info("获取用户优惠券列表，用户ID: {}, 订单金额: {}", userId, orderTotalPrice);
        return new ArrayList<>();
    }

    @Override
    public Object calculatePointsDiscount(Long userId, BigDecimal orderTotalPrice) {
        // TODO: 实现积分抵扣计算
        // 1. 获取用户积分余额
        // 2. 获取积分抵扣设置
        // 3. 计算可抵扣积分和金额
        Map<String, Object> pointsInfo = new HashMap<>();
        pointsInfo.put("isAllowPoints", false);
        pointsInfo.put("pointsMoney", BigDecimal.ZERO);
        pointsInfo.put("pointsNum", 0);
        log.info("计算积分抵扣，用户ID: {}, 订单金额: {}", userId, orderTotalPrice);
        return pointsInfo;
    }

    @Override
    public List<Object> getDeliveryTypes() {
        // TODO: 实现配送方式获取
        // 1. 从系统设置获取支持的配送方式
        // 2. 返回配送方式列表
        List<Object> deliveryTypes = new ArrayList<>();
        Map<String, Object> express = new HashMap<>();
        express.put("value", 10);
        express.put("text", "快递配送");
        deliveryTypes.add(express);
        
        Map<String, Object> extract = new HashMap<>();
        extract.put("value", 20);
        extract.put("text", "到店自提");
        deliveryTypes.add(extract);
        
        return deliveryTypes;
    }

    @Override
    public BigDecimal calculateDeliveryFee(Long addressId, List<CartResponseParam.CartGoodsInfo> goodsList) {
        // TODO: 实现配送费用计算
        // 1. 根据收货地址计算配送费用
        // 2. 考虑满额包邮等规则
        log.info("计算配送费用，地址ID: {}, 商品数量: {}", addressId, goodsList.size());
        return BigDecimal.ZERO;
    }
}
